Ripping an ISO of a disc I own - volume key unknown?

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yonis
Posts: 4
Joined: Wed Jul 21, 2010 3:21 am

Ripping an ISO of a disc I own - volume key unknown?

Post by yonis » Thu Feb 08, 2018 3:45 pm

I bought a new copy of X-Men Apocalypse in UHD, but encountered I/O errors when reading the disc with MakeMKV. It'll decrypt the disc fine, but then fail to fully rip the disc about a third of the way in.

I was able to extract the data from the disc by painstakingly reading 100 MB chunks of the disc in dd, ejecting and reinserting the disc when I/O errors occurred, then joining the chunks together to an ISO using cat.

I can perfectly browse the ISO in Finder, but when I try to open it in MakeMKV, it complains that the volume key is missing and can't decrypt it.

Code: Select all

MakeMKV v1.12.0 darwin(x64-release) started
The program can't find any usable optical drives.
Using direct disc access mode
Saved AACS dump file as [...]/Library/MakeMKV/MKB20_v61_X-Men_Apocalypse_BE17.tgz
The volume key is unknown for this disc - video can't be decrypted
Failed to open disc
Since I have the disc I ripped the ISO from, how can I get MakeMKV to decrypt the ISO the same way it can with my original disc?

TeddyRaspin
Posts: 105
Joined: Thu Dec 28, 2017 1:41 pm

Re: Ripping an ISO of a disc I own - volume key unknown?

Post by TeddyRaspin » Thu Feb 08, 2018 4:05 pm

If a VUK for your version is unknown, you have to send first the generated dump to Mike in order to have the VUK added in the keys_hashed.txt file.

Then you will be able to properly decrypt either original disc or protected iso. :wink:

preserve
Posts: 361
Joined: Sun Sep 13, 2015 10:21 pm
Location: Canada

Re: Ripping an ISO of a disc I own - volume key unknown?

Post by preserve » Thu Feb 08, 2018 4:31 pm

TeddyRaspin wrote:If a VUK for your version is unknown...
Nope, that's not the issue :)
yonis wrote:It'll decrypt the disc fine, but then fail to fully rip the disc about a third of the way in.
A few people have posted similar issues but I'm not sure if a definitive solution has been found. Could be an issue with the drive, what drive are you using? Debug log?
Using: ASUS BW-16D1HT 3.00 || UHD FAQ - If you're new to UHD, read it!

mike admin
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Joined: Wed Nov 26, 2008 2:26 am
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Re: Ripping an ISO of a disc I own - volume key unknown?

Post by mike admin » Thu Feb 08, 2018 8:24 pm

yonis wrote:Since I have the disc I ripped the ISO from, how can I get MakeMKV to decrypt the ISO the same way it can with my original disc?
Yes, if you have made the iso from exactly the same disc, with exactly the same drive on exactly the same firmware version.
You will need to unpack the iso (with winrar, or mount and copy all files from) to a folder #1.
Then you need to start MakeMKV and make a non-decrypted full disc backup, from the same disc and in the same drive, to another folder #2.
The moment MakeMKV starts copying the files, abort the backup, eject the disc, quit MakeMKV.
Copy file discatt.dat from folder #2 to folder #1
Delete folder #2
Folder #1 is now a non-decrypted full disc backup. You can open it in MakeMKV as usual.

yonis
Posts: 4
Joined: Wed Jul 21, 2010 3:21 am

Re: Ripping an ISO of a disc I own - volume key unknown?

Post by yonis » Fri Feb 09, 2018 3:35 am

mike admin wrote:Yes, if you have made the iso from exactly the same disc, with exactly the same drive on exactly the same firmware version.
You will need to unpack the iso (with winrar, or mount and copy all files from) to a folder #1.
Then you need to start MakeMKV and make a non-decrypted full disc backup, from the same disc and in the same drive, to another folder #2.
The moment MakeMKV starts copying the files, abort the backup, eject the disc, quit MakeMKV.
Copy file discatt.dat from folder #2 to folder #1
Delete folder #2
Folder #1 is now a non-decrypted full disc backup. You can open it in MakeMKV as usual.
Thank you! This worked perfectly!

For what it's worth, I have the Asus BW-16D1HT, 3.02 firmware (updated from 3.0), in a Vantec NST-536S3-BK NexStar DX USB enclosure. I've ripped a few UHD discs with MakeMKV alone, but sometimes these (brand-new) discs produce I/O errors partway through ripping.

I wrote a script to clone segment by segment, and toss any segments with I/O errors in them, reripping just those segments after re-inserting the disc. Happy to know that my hacky workaround can work with MakeMKV!

crackers8199
Posts: 4
Joined: Thu Mar 08, 2018 9:11 am

Re: Ripping an ISO of a disc I own - volume key unknown?

Post by crackers8199 » Thu Mar 08, 2018 5:47 pm

yonis wrote:
mike admin wrote:Yes, if you have made the iso from exactly the same disc, with exactly the same drive on exactly the same firmware version.
You will need to unpack the iso (with winrar, or mount and copy all files from) to a folder #1.
Then you need to start MakeMKV and make a non-decrypted full disc backup, from the same disc and in the same drive, to another folder #2.
The moment MakeMKV starts copying the files, abort the backup, eject the disc, quit MakeMKV.
Copy file discatt.dat from folder #2 to folder #1
Delete folder #2
Folder #1 is now a non-decrypted full disc backup. You can open it in MakeMKV as usual.
Thank you! This worked perfectly!

For what it's worth, I have the Asus BW-16D1HT, 3.02 firmware (updated from 3.0), in a Vantec NST-536S3-BK NexStar DX USB enclosure. I've ripped a few UHD discs with MakeMKV alone, but sometimes these (brand-new) discs produce I/O errors partway through ripping.

I wrote a script to clone segment by segment, and toss any segments with I/O errors in them, reripping just those segments after re-inserting the disc. Happy to know that my hacky workaround can work with MakeMKV!

can you share your script? i'm trying to salvage an apparently damaged blu ray but not having any luck getting past a certain spot. i was able to get ddrescue to produce an iso and then decrypt it similar to the procedure detailed here, but it still fails at the same spot complaining of corrupted files...

dafolsom
Posts: 6
Joined: Sat Jan 26, 2019 9:54 pm

Re: Ripping an ISO of a disc I own - volume key unknown?

Post by dafolsom » Thu Jan 31, 2019 4:12 am

I know this is an old topic, but I have been trying for an hour now to figure out how to produce the discatt.dat file as described by Mike in this thread. I have a couple questions that, if answered, might clarify this for me:
  • Is a "non-decrypted full disk backup" any different than the usual process of making a backup?
    At what point in the process does MakeMKV "start copying the files"? While "Saving to MKV file"? While "Saving all titles to MKV files"?
At no point can I see the creation of the discatt.dat file in the destination folder and when I abort the process and close the app. the folder contents are deleted.

Any help would be appreciated. Thanks.

Woodstock
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Joined: Sun Jul 24, 2011 11:21 pm

Re: Ripping an ISO of a disc I own - volume key unknown?

Post by Woodstock » Thu Jan 31, 2019 1:55 pm

Non-decrypted backup is, "Start a backup, uncheck the "decrypt files" checkbox, and let it run for a moment". Pretty much any time after you start getting messages about writing files, you can stop the backup, and discatt.dat will have been created.
How to aid in finding the answer to your problem: https://www.makemkv.com/faq/item/8

dafolsom
Posts: 6
Joined: Sat Jan 26, 2019 9:54 pm

Re: Ripping an ISO of a disc I own - volume key unknown?

Post by dafolsom » Fri Feb 01, 2019 2:36 am

Got it! Thanks so much.

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